What material is issued for one-time installation in specified equipment during fleet maintenance overhaul, repair, or modification programs?

The material issued for one-time installation in specified equipment during fleet maintenance overhaul, repair, or modification programs is known as TD Kits, or Technical Directive Kits. These kits are specifically designed to implement technical directives that stem from the maintenance instructions or requirements for a specific piece of equipment.

TD Kits typically include all necessary components, documentation, and instructions required for the proper installation or modification as dictated by the technical directive. This focused approach ensures that the equipment meets updated standards and integrates the latest improvements or repairs mandated for operational readiness.

In contrast, maintenance kits are used for general upkeep rather than one-time installations, repair parts refer to components that may be used multiple times for repairs, and operational kits involve materials for ongoing operations rather than specific installations per directive. Thus, TD Kits distinctly fulfill the requirement for singular application during maintenance activities, making them the correct answer for this scenario.